Narrative:

During cruise swbound on V39, ATC called traffic at about 10:30-11 O'clock position and 10-12 mi. I sighted the traffic, which was 2000-3000 ft below me, and was instructed to maintain visual separation while the traffic climbed through my altitude. I was swbound, traffic was nwbound. Based on prior experience, I expected the traffic, an airbus, to pull ahead and climb above me prior to our paths crossing. As I kept the traffic in sight, it did initially seem to be accelerating ahead of me, but continued observation indicated that it was not by much. Consequently, I began a gentle turn to the right to open the point of intersection. As the traffic continued to close and climb, it became obvious that we would pass very close, and I commenced a turn to the left to pass behind the traffic, with a very high closure. At this point, I also began to climb. As the traffic passed directly beneath at about 1000 ft he reported that he had stopped his climb. He also appears to have been in a right turn, thus we had each turned into the other. I believe that the potential for a collision was very high -- this in spite of the fact that I had continuous, unbroken visual contact from start to finish. I found it very difficult to judge the relative motion of the other aircraft while it was climbing and closing simultaneously. I also found that, since I was in cruise along an airway and the other aircraft was 'maneuvering,' I was reluctant to make dramatic changes in heading, a reluctance that was fed by my expectation that the jet would pull out ahead and above. Further, by the time it became obvious to me that my expectations were not bearing out, our 2 aircraft were quite close, and closing fast. The situation developed very rapidly in its latter stages. Some observations suggestions: 1) the controller should have been able to see that our aircraft were on collision courses, or close to it, and thus should not have issued visual separation instructions. 2) lacking an obvious and dramatic bearing change, I should not have accepted visual separation responsibility. 3) when visual separation is used between an aircraft in cruise and one that is 'maneuvering,' it should be the 'maneuvering' aircraft that maintains separation. In this case, we both were maneuvering at the end, and evidently at cross purposes. In the future, I will not accept visual separation when the above criteria are not met. In retrospect, it would have required an almost immediate 45 degree heading change on my part to maintain comfortable lateral separation.

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Original NASA ASRS Text

Title: AN ACR LTT CAPT REGRETS HAVING ACCEPTED VISUAL SEPARATION FROM A CLBING ACR LGT.

Narrative: DURING CRUISE SWBOUND ON V39, ATC CALLED TFC AT ABOUT 10:30-11 O'CLOCK POS AND 10-12 MI. I SIGHTED THE TFC, WHICH WAS 2000-3000 FT BELOW ME, AND WAS INSTRUCTED TO MAINTAIN VISUAL SEPARATION WHILE THE TFC CLBED THROUGH MY ALT. I WAS SWBOUND, TFC WAS NWBOUND. BASED ON PRIOR EXPERIENCE, I EXPECTED THE TFC, AN AIRBUS, TO PULL AHEAD AND CLB ABOVE ME PRIOR TO OUR PATHS XING. AS I KEPT THE TFC IN SIGHT, IT DID INITIALLY SEEM TO BE ACCELERATING AHEAD OF ME, BUT CONTINUED OBSERVATION INDICATED THAT IT WAS NOT BY MUCH. CONSEQUENTLY, I BEGAN A GENTLE TURN TO THE R TO OPEN THE POINT OF INTXN. AS THE TFC CONTINUED TO CLOSE AND CLB, IT BECAME OBVIOUS THAT WE WOULD PASS VERY CLOSE, AND I COMMENCED A TURN TO THE L TO PASS BEHIND THE TFC, WITH A VERY HIGH CLOSURE. AT THIS POINT, I ALSO BEGAN TO CLB. AS THE TFC PASSED DIRECTLY BENEATH AT ABOUT 1000 FT HE RPTED THAT HE HAD STOPPED HIS CLB. HE ALSO APPEARS TO HAVE BEEN IN A R TURN, THUS WE HAD EACH TURNED INTO THE OTHER. I BELIEVE THAT THE POTENTIAL FOR A COLLISION WAS VERY HIGH -- THIS IN SPITE OF THE FACT THAT I HAD CONTINUOUS, UNBROKEN VISUAL CONTACT FROM START TO FINISH. I FOUND IT VERY DIFFICULT TO JUDGE THE RELATIVE MOTION OF THE OTHER ACFT WHILE IT WAS CLBING AND CLOSING SIMULTANEOUSLY. I ALSO FOUND THAT, SINCE I WAS IN CRUISE ALONG AN AIRWAY AND THE OTHER ACFT WAS 'MANEUVERING,' I WAS RELUCTANT TO MAKE DRAMATIC CHANGES IN HDG, A RELUCTANCE THAT WAS FED BY MY EXPECTATION THAT THE JET WOULD PULL OUT AHEAD AND ABOVE. FURTHER, BY THE TIME IT BECAME OBVIOUS TO ME THAT MY EXPECTATIONS WERE NOT BEARING OUT, OUR 2 ACFT WERE QUITE CLOSE, AND CLOSING FAST. THE SIT DEVELOPED VERY RAPIDLY IN ITS LATTER STAGES. SOME OBSERVATIONS SUGGESTIONS: 1) THE CTLR SHOULD HAVE BEEN ABLE TO SEE THAT OUR ACFT WERE ON COLLISION COURSES, OR CLOSE TO IT, AND THUS SHOULD NOT HAVE ISSUED VISUAL SEPARATION INSTRUCTIONS. 2) LACKING AN OBVIOUS AND DRAMATIC BEARING CHANGE, I SHOULD NOT HAVE ACCEPTED VISUAL SEPARATION RESPONSIBILITY. 3) WHEN VISUAL SEPARATION IS USED BTWN AN ACFT IN CRUISE AND ONE THAT IS 'MANEUVERING,' IT SHOULD BE THE 'MANEUVERING' ACFT THAT MAINTAINS SEPARATION. IN THIS CASE, WE BOTH WERE MANEUVERING AT THE END, AND EVIDENTLY AT CROSS PURPOSES. IN THE FUTURE, I WILL NOT ACCEPT VISUAL SEPARATION WHEN THE ABOVE CRITERIA ARE NOT MET. IN RETROSPECT, IT WOULD HAVE REQUIRED AN ALMOST IMMEDIATE 45 DEG HDG CHANGE ON MY PART TO MAINTAIN COMFORTABLE LATERAL SEPARATION.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.